Tuesday, January 05, 2010

Yesterday, I was back at Tanah Merah with a few friends. As usual, night time at Tanah Merah was a lot livelier with more organisms coming out to feed.

The flatworms are one of the animals which are more active at night. This is an Acanthozoon Flatworm (Acanthozoon sp.), one of the more common flatworms that we can see on our shores.

Pseudobiceros uniarborensis is another flatworm often seen on our shores. It has a bright orange line running by the edge of its mantle.

This should be my favourite flatworm of the night, a Pseudobiceros gratus.

As we were exploring, we noticed quite a number of these little flatworms. They looked like juvenile Pseudobiceros stellae to me, but were really a little small to say for sure.

Yet another night animal will be the moon snails, such as this Natica zonalis that had a really pretty orange shell with a pinkish head and striped foot.

The Ghost Crabs (Ocypode ceratophthalma) were particularly active at night, foraging for small animals to feed. I saw one feeding on a smaller crab that was still alive! Did not managed to get any photos of that one though. It ran too fast.

Swimming Crabs (Thalamita spp.) were really abundant here too, though most of them were rather small. They got their common name because they can swimming really well, using their paddle-like back legs to propel them around.

One other crab that we spotted was this Velcro Cab (Camposcia retusa), which was really a master of camouflage, provided it was among the rocks, of course, unlike this one which was on the sand. It has tiny hair on its exoskeleton, acting like velcro which allows sponges and algae to stick to it, helping it to blend into surrounding rocks.

The sandy surrounding would probably be more suited for this scallop, camouflaging it nicely. But apart from being able to blend into the surrounding, a scallop is able to escape predation by swimming away quickly too. It does so by flapping its shells and creating a jet propulsion as it closes its shell quickly.

Yet another master of camouflage in the sandy area would be this flatfish. Just look at how its colour blended into the surrounding sand. And that's not all. It could also flap its fins to stir up the sediment to cover its body to conceal it from predators and prey. Interestingly, this fish had both its eyes on one side of its body, hence allowing it to lay down on one side to flatten itself against the sand for better camouflaging.

However, not all fishes laid down on one side by choice. This poor Cardinalfish (Cheilodipterus sp.) was probably stranded in a shallow pool by the receding tide.

This False Scorpionfish (probably Centrogenys vaigiensis) was another unlucky one. While this fish had spines on its dorsal fins, it's not venomous like the scorpionfish that it's mimicking.

This fellow was the real venomous Scorpionfish (probably Parascorpaena picta) with venomous spines, which could gave extremely painful stings to anyone who accidentally step on it barefooted.

Unlike the scorpionfish which stings for defence, this tube anemone stung and trapped tiny plankton or small animals to feed on.

Like the tube anemone, these fan worms also feed on plankton and other tiny food particles from the water. They, however, do not sting, but rely on their crown of feather-like tentacles to trap their food.

Also armed with tentacles, this synaptid sea cucumber pick up tiny food particles from its surrounding by lashing these oral tentacles around.

The Sandfish Sea Cucumber (Holothuria scabra) also has oral tentacles, which it used to feel and pick up sand rich with organic matter to feed on. It got its name from its ability to burrow into the sand to hide from predators and to find food.

Indeed, the sandy habitat is the perfect place to live in for burrowers. The Sand-sifting Sea Star (Archaster typicus) is one of them. This particular sea star had only three arms, unlike the usual ones with five arms.

And we explored and walked on, we eventually reached the area that Kok Sheng had wanted to visit - the area with soft corals and allied cowries! Upon reaching the area, we found a pink soft coral with one allied cowrie.

I soon spotted another one with two of them! Well, mission accomplished!

Heard from James later that they approached a fisherman who showed them a huge sea cucumber. From his photo, it had the general look and feel of a Stichopus hermanni, but the coloration was not one which I have seen before, so can't really say for sure.

Quite a pity that this huge sea cucumber probably ended up in the cooking pot, but guess that's something happening every now and then in Singapore. Certainly hope that we can have a Marine Park soon where the marine life will get more protection.